DESIGN OF SANDWICH STRUCTURES INCLUDING A POLYMERIC/ELECTRICALLY NON-CONDUCTING CORE FOR WELDABILITY

• US 20160200074A1
• Filed: 01/14/2015
• Published: 07/14/2016
• Est. Priority Date: 01/14/2015
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: LANG, STEVEN C., MANKAME, NILESH D., CAI, WAYNE W.
• Granted Patent: US 10,086,587 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23K 11/11 Spot welding
• CPC Class Codes: B23K 11/115 by means of two electrodes placed opposite one another on both sides of the welded parts
• CPC Class Codes: B23K 11/20 of different metals
• CPC Class Codes: B23K 20/122 using a non-consumable tool, e.g. friction stir welding
• CPC Class Codes: B23K 20/129 specially adapted for particular articles or workpieces
• CPC Class Codes: B23K 20/2275 the other layer being aluminium
• CPC Class Codes: B23K 2101/006 Vehicles
• CPC Class Codes: B23K 2101/02 Honeycomb structures
• CPC Class Codes: B23K 2101/185 Tailored blanks
• CPC Class Codes: B23K 2103/166 Multilayered materials
• CPC Class Codes: B23K 2103/20 Ferrous alloys and aluminium or alloys thereof
• CPC Class Codes: B23K 26/22 Spot welding
• CPC Class Codes: B23K 26/323 involving parts made of dissimilar metallic material
• CPC Class Codes: B23K 31/02 relating to soldering or welding dip or wave soldering in the manufacture of printed circuits H05K3/34
• CPC Class Codes: B32B 15/012 one layer being formed of an iron alloy or steel, another layer being formed of aluminium or an aluminium alloy
• CPC Class Codes: B32B 15/043 of metal B32B15/01 takes precedence
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2307/206 Insulating
• CPC Class Codes: B32B 2307/752 Corrosion inhibitor
• CPC Class Codes: B32B 2605/08 : Cars
• CPC Class Codes: B32B 27/16 : specially treated, e.g. irradiated
• CPC Class Codes: B32B 3/08 : characterised by added members at particular parts layer formed of separate pieces of material which are juxtaposed side-by-side B32B3/14, B32B3/18
• CPC Class Codes: B32B 3/12 : characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
• CPC Class Codes: B32B 3/266 : characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12

Abstract

A technique for welding two dissimilar metal panels or structures together, such as vehicle structures, by providing a sandwich structure between the dissimilar metal structures that includes one skin being made of the same metal as one of the metal structures and an opposing skin being made of the same metal as the other metal structure, and including an electrically non-conducting core between the skins.

Claims

1. A welding assembly comprising:

a first structure being made of a first metal;

a second structure being made of a second metal that is different than the first metal; and

a sandwich structure positioned between the first structure and the second structure, said sandwich structure including a first skin being made of the first metal and positioned against the first structure, a second skin being made of the second metal and positioned against the second structure and an electrically non-conducting core positioned between the first skin and a second skin.

2. The assembly according to claim 1 wherein the sandwich structure is a micro-truss structure and the electrically non-conducting core is a micro-truss core.

3. The assembly according to claim 1 wherein the sandwich structure includes an electrically non-conducting mechanical support positioned within the core at the site of a weld joint and being in contact with the first skin and the second skin.

4. The assembly according to claim 3 wherein the sandwich structure includes an insert positioned around the support that includes cooling fluid flow channels.

5. The assembly according to claim 1 wherein the welding assembly is a resistance spot welding assembly including a spot welding electrode positioned against the first structure opposite to the first skin at a point in time and a spot welding electrode positioned against the second structure opposite to the second skin at a point in time.

6. The assembly according to claim 5 further comprising a conductive stud electrically coupled to the first skin and being in electrical communication with the electrode positioned against the first structure and a conductive stud electrically coupled to the second skin and being in electrically communication with the electrode positioned against the second structure.

7. The assembly according to claim 5 further comprising other spot welding electrodes, wherein the second structure and the core include a first set of aligned openings where one of the other welding electrodes extends through the first set of aligned openings to contact the first skin opposite to the electrode positioned against the first structure, and the first structure and the core include a second set of aligned openings where another spot welding electrode extends through the second set of aligned openings to contact the second skin opposite to the electrode positioned against the second structure.

8. The assembly according to claim 1 wherein the welding assembly is a friction stir welding assembly, said welding assembly further comprising a friction stir welding probe positioned against the first structure opposite to the first skin at a point in time and a friction stir welding probe positioned against the second structure opposite to the second skin at a point in time.

9. The assembly according to claim 1 wherein the welding assembly is a laser welding assembly.

10. The assembly according to claim 9 wherein the core includes a void or divot adjacent to a location where the laser welding occurs.

11. The assembly according to claim 1 wherein the first metal is steel and the second metal is aluminum.

12. The assembly according to claim 1 wherein the first and second structures are vehicle structures.

13. A method for welding two structures together, said method comprising:

providing a first structure being made of a first metal;

providing a second structure being made of a second metal that is different than the first metal;

providing a sandwich structure positioned between the first structure and the second structure, said sandwich structure including a first skin being made of the first metal and positioned against the first structure, a second skin being made of the second metal and positioned against the second structure and an electrically non-conducting core positioned between the first skin and a second skin; and

welding the first structure to the first skin and welding the second structure to the second skin.

14. The method according to claim 13 wherein providing a sandwich structure includes providing a sandwich structure that is a micro-truss structure where the electrically non-conducting core is a micro-truss core.

15. The method according to claim 13 wherein providing a sandwich structure includes providing a sandwich structure having an electrically non-conducting mechanical support positioned within the core and being in contact with the first skin and the second skin.

16. The method according to claim 15 wherein providing a sandwich structure includes providing a sandwich structure having an insert positioned around the support that includes cooling fluid flow channels.

17. The method according to claim 13 wherein the method is a resistance spot welding method, said method further comprising positioning a spot welding electrode against the first structure opposite to the first skin at a point in time and positioning a spot welding electrode positioned against the second structure opposite to the second skin at a point in time.

18. The method according to claim 17 further comprising electrically coupling a first conductive stud to the first skin and the electrode positioned against the first structure and electrically coupling a second conductive stud to the second skin and the electrode positioned against the second structure.

19. The method according to claim 17 further comprising providing other spot welding electrodes, a first set of aligned openings through the second structure and the core, and a second set of aligned openings through the first structure and the core, and extending one of the welding electrode through the first set of aligned openings to contact the first skin opposite to the first electrode, and extending one of the welding electrodes through the second set of aligned openings to contact the second skin opposite to the second electrode.

20. The method according to claim 13 wherein the method is a friction stir welding method, said method further comprising positioning a stir welding probe against the first structure opposite to the first skin at a point in time and positioning a stir welding probe against the second structure opposite to the second skin at a point in time.

21. The method according to claim 13 wherein the method is a laser welding method.